Bar feed for lathes



May 22,' 1945. H H, LOGAN BAR FEED FOR LATHEs 4 Sheets-Sheet l Filed Feb. 24, 1943 May 22, 1945. H. H. LOGAN BAR FEED lFor: LATHE'S 4 Sheets-Sheet 2 Filed Feb. 24, 1943 May 22, 1945. v H. Hg LOGAN 2,676,666

BAR FEED FOR LATHES Filed Feb. 24, 1943 4 sheets-'sheet 5 `May 22, 1945.. H* LOGAN BAR FEED FOR LATHES 4 Sheets-Sheet 4 Filed Feb. 24, 1943 Patented May 22, 1945 BAR FEED Fon LATHES Henry'H. Logan; Chicago, Ill., assigner to Logan l Engineering Co., Chicago,-'Ill., a corporation of' Illinois Y Application February 24, 1943,2Serial'No. 476,883

(Cl. 12S-59) 6 Claims.

Myv invention relates to theso-called bar feeds for lathes; especially turret lathes. v Such a-bar feed advances a bar through theV hollowspindle of the lathe to supplysuccessive lengths of bar stock. Since the barsrota'tathey must be locked againstrota'ry and axial movement` relative to the spindle, which is usually done by a collet in the nose of thev spndlewhich4 is tightened and released by cam-controlled. fingers operating on thet'ail end ofv a sleeve slidablewithin the spindle and. aboutthe bar., For conveniencevthe locking and releasing of thecollet is vusually incorporated as an incidentto the. operation of the bar. feed proper, wherebythe steps yof releasing thecollet, advancingthe bar,\tightening the collet, andretracting the feedmecha-nism preparatory to the next advance,isf all done within the cycle of a Asingle operating lever.

One objection to such bar feeds'hasbeen that the sliding sleeve which controls the collet-operating `fingers has hadto slide along the spindle not only the distance required for tightening or releasing the collet, but also; additionally, the

Another feature -of myi invention is that my mechanism which reciprocates .the collet-controlling sleeve and which reciprocates the bar feed ratchet is unusually compact, forms a smallunit readily attached to theend of the headstock, and

presents its singley controlling lever ina position distance equivalent tothe distance the bar stock is shiftedat eachlfeed.' If the lathev were to be usedponly for making ,relatively short' parts from the bar stock, so that the feed distance would be short, this added movement ofthe sleevewould not besaobjectionable. But since the work often involves a considerable feed distance and the bar feed mechanism of thel lathe must therefore be built toaccommodate it, there has followed vthe serious objection that the lathe spindle and the collet-shifting tube have had tobe builtwith considerable extra Alengthto accommodate :the feed movement. These objections have included the necessity of an extra long lathe spindle, theadded steel requiredfor it,V the greater` production'difculties occasioned by thel longer bore which must be true, extra space, thez'long overhang beyond thel headstockbar, and the consequent tendency to instability Vand vibration..`

A major object of my invention is to provide a .bar -feedmechanism,V incorporating' the locking and releasing of the collet, wherein thecam sleeve for releasing the collet` fingers and other axially shifted parts incident tothe collet control, need shiftaxially of the spindle -onlysofar as the collet .locking and releasing itself requires, to the exclusion of any added shifting distance required for the. bar feed.itself.. Thereby the application of my bar feed mechanism and collet control to a lathe involves but a Vminimum, extra. spindle length.

most convenient to thevoperator.

The foregoing, together with further objects., features, and advantages of my invention, are set forth in the following description of a specic embodiment thereof as illustrated inthe accompanying drawings.I wherein? Fig. 1 is a side elevation of the headstock of a lathe showing my bar Afeed mechanism and the supports for the bar stock;

Fig. 2 is a detail thereof partly in vertical longitudinal section;.

Fig. v3 is a side elevation of the` bar'feed mechanisrni of Fig. 2 with the parts in the Asame position as Fig; 2, thatis, with the col-let locked;

Fig. 4 is a side elevation like Fig.13 exceptthat the. mechanism has been advanced `,to an intermediatepoint where thel release ofthe collet has been accomplished but thev barlhas not Ibeen fed;

Figli isa sideielevation likeFigs. 3 and 4 except that they mechanism khas been advanced to its farthest `position toeffect the barfeed;V

Fig.6 is 1a transverse vertical section looking toward :the headstock of the lathetaken on the line 6-'6 of'Fi'gsf2v and: 3; f.

Fig. 7 is a transverse vertical sectionthrough theubarA vfeed carrier taken on the 1in`e-1-1 of F'g'.;'5;`

Figi: 8 l(Sheet 2). isxa perspective view of the frame memberofthe shifting mechanism; and

Fg.r9 `(Sheet 3) is a back'vside'elevation of the shifting mechanism in the lower righthand corneriofFig. 3.

Theheadstock' l0 ofthe lathe journals'a spindie llwhich at its `nose carries a collet-I2. A colletecontrolling tube I3` runs back through the spindle ll andrabout the bar B. A spring I4, interposed between `the qend-of the spindle Il. and a collar at the end of the tube I3; yurges thel tube backwardly'tending torelease the collet'.

Diametrically opposed ngers I5 are pivoted on 'a head I6 threaded onto'the end ofthe spindle and xed bya lock nut Iv'l. The inwardly olfset ends of the fingers abut the end of the tube I3' whereby 'a radial spreading of the free ends of the fingers willpush the tube. forwardly against the resilience of the spring I4 to lock the collet upon the bar B. Spreadingof the 1ingers |5` and their return movement underthe urging of the spring I4 is controlled by the rounded end of the cam sleeve I8 slidably mounted on the spindle and shifted by a yoke I9. I shall subsequently describe the mechanism whereby the yoke I9 is rocked to effect the locking and releasing of the collet.

A long length of the bar stock B is rotatably supported in bushings in the upper ends of near and far standards 2| and 22. A long ratchet bar 23 is slidably mounted splinewise in a longitudinal groove along the upper side of a guide rod 24. The far end of the guide rod is fixed in the near standard 2|; its near end is supported in the headstock as shown in Fig. 2.

A bar feed carrier 25 has a lower hub 25a whereby it is slidably mounted upon the guide rod 24. It; has a hushed upper eye 25D through which the bar B extends.r The hub 25a also receives and passes the ratchet bar 23. A cross bore 25e (see Fig. 7 also) just above the guide rod and ratchet bar journals a pawl 28 which, by virtue of the weight of its obliquely mounted handle 28a, tends to swing down into engagement with the teeth of the ratchet bar 23. The pawl can be disengaged by lifting the handle 28a as limited by a stop pin 25e on the carrier.

A stop collar 26 xed upon the bar B by a set screw 26a is adapted to abut the eyed upper end of the carrier 25 whereby to shift the bar longitudinally into the spindle when the carrier is shifted by the shifting of the ratchet bar in that direction.

The carrier 25 is frictionally locked to the guide rod 24 with the aid of a plug brake 29 working in the downwardly opening vertical bore 25d of the carrier, which plug brakeis urged against the bottom of the guide rod by a spring 29a adjustably compressed by a screw plug 29h.

Thus a, latheward pull on the ratchet bar 23 will engage the pawl 28 and thereby shift the carrier 25 which, abutting the collar 26, will shift the bar B into the lathe. On the other hand, shifting of the ratchet bar 23 in the opposite directionaway from the lathe-will not shift the carrier because the carrier is frictionally locked to the guide rod 24 and the ratchet bar,

on retrogression, will ratchet past the pawl 28.

I shall now describe the mechanism for shifting the cam sleeve I8 to effect the locking and unlocking of the collet and for reciprocating the ratchet bar 23v to effect the bar feed, taking up the former rst.

This shifting mechanism is mounted on a frame 3|, the shape of which is best seen from Fig. 8. It is detachably xed upon the headstock of the lathe by a boss 3|a which fits into a bearing bore 32 in the headstock, and by a pair of cap screws 33 passing through laterally spaced holes 3 Ib in the frame and entering tapped holes in the end of the headstock provided for the purpose of attaching accessories. The reduced inner end 24a of the guide rod 24 passes through the boss 3Ia and receives the nut 2417, whereby the guide rod 24, at its inner end, is xed to, and supported by, the frame 3 I.

The laterally spaced upper wings 3|c of the frame 3| mount the bearing pin 36a. of a colletshifting rocker 36, the bearing pin passing through rides in an annular groove in the cam sleeve I8. Thereby rocking of the rocker 36 will shift the cam sleeve I8 to effect locking and releasing of the collet through the fingers I5 and the tube I3. Rocking of the collet-shifting rocker 36 is effected by means of an arm 36d depending at the front side thereof and carrying a horizontally outstanding stud pin 36j bearing a roller 36g.

The roller 36g of the collet-shifting rocker 36 rides in the slot of a collet-shifting cam 31, 'the hub 31e of which is fixed upona cam shaft 38. The cam shaft 38 is transversely and horizontally journaled in bearings 3 Id in the sides of the frame 3| somewhat below the guide rod 24. On its forward end the cam shaft 38 carries an upstanding hand lever 39.

The slot of the collet-shifting cam 3`I in which the roller 36g of the collet-shifting rocker 36 rides, comprises two successive portions--a cam slot 31a and a dwell slot 3'Ib arcuately described about the axis of the shaft 38. These two portions of the slot of the cam 31 are so arranged that as the lever 39 is pulled toward the headstock by the operator from the normal position of Figs. 1, 2 and 3, the roller 36g will first ride in the cam slot 37a with the result that it will be thrown out to a greater radius from the cam shaft 38 and thereby rotate the collet-shifting rocker 36 clockwise to shift the finger cam sleeve I8 toward the headstock, thereby releasing the fingers I5 to permit the spring I4, acting through the tube I3, to release the collet. By the time the lever 39 has been shifted to its intermediate vertical position of Fig. 4 and the roller 36g has reached the end of the cam slot 31a and the beginning of the dwell slot 3'Ib, movement of the collet-shifting rocker 36 will have been terminated and further movement of the handle and the cam 31 will merely hold the rocker 36 in its position of Fig. 4.

I shall now describe that part of the shifting mechanism which effects the bar feeding shift of the ratchet bar 23. y

At the back side of the mechanism the back end of the cam shaft 38 carries a bar feed cam 40, the slot of lwhich-in a somewhat similar manner but in reverse order as compared with the lcollet-shifting cam 3`I-comprises a cam slot 46a and a dwell slot 40h. In this slot rides a roller 4| a borne by a stud pin 4Ib protruding from the back side of a bar feeding rocker 4I. The rocker 4I is journaled on the frame 3| by means of a transverse bearing pin 4Id extending through the lower hub 4|c of the rocker and fixed at its ends in a pair of laterally spacedlower bearings 3| e depending from the frame 3| as 4best shown in Fig. 6. l

At its upper end the bar feeding rocker 4I carries a pair of laterally spaced arms 4Ie, the upper end of each of which in turn is forked to receive the respective trunnions 42a of a ratchet bar collar 42. The collar 42 is slotted at 42h to receive the head formed at the inner end of the ratchet bar 23. The collar 42 surrounds and is shiftable along the guide rod 24, under the control of the bar feeding rocker 4I, which in turn is controlled by the bar feed cam 46 xed to the same shaft as the lever 39. The cam slot 40a and the dwell slot 48h in the bar feed cam 40 are so disposed and arranged that when the leyer 39 is pulled from its normal position of Figs. 1, 2 and 3 to its intermediate position of Fig. 4 to effect release of the collet, the bar feeding rocker 4I is not rocked and consequently there is no :feedingrmirvemehtinrnarted tothe bar. This vis inzerder. becausethe-bar should notbesubjected toll'fedaruntil ithe; collet 'which locks 1 it has been released l. l

Gontinuedeforward-fpull'. of the lever Berbeyend its.intermediatelverticalposition of Fignl brings the roller 41a .ofthe bar feeding rocker il out ofthe dwellslotidh of the bar feed mechanism Il andlinto the cam slot whereupon the bar feedingr.frocker;4IV isl swung to shift its-,.forkedarms l He towardthe headstock aand hence, by ymeans @futile.ratohetbarlcollar 42e, to drawthe ratchet barwz towardtheheadstock because the pawl 2&tllenxengages the teeth `0f, the ratchet bar 23,.

Thefcarrierrz: is lkeWiseashifted, pressing against thastop collar; 2li to effect the desired feed of the banBas ,limtedzhy the stop usuallyprovided on the turretfor fon the I tail; stock.

It will. beiwiderstood 'that by modifying the disposition lof the;cam slotzdta of-therbar feed headstokxtoa nosition'where, save for-the in.-

terruption; inY they ratchet-har teeth, the carrier wouldabut-thecollarllZ. Wbenthatpr-ogression ofthe carrier is-reached, ,the operator lifts the handlewoflthe pawlrto disengage it from the ratohetbar teeth; slidesthe carrier back tc the. standard 12|, drops thepavvl, andl resets the stop collar 26 to abut the carrier-infitsnewposition. Thisgresetting Visrepeated from time to time until the length of the bar B is exhausted. An arched cover or shield 43 is set over the cam sleeve I8, fingers I and head I6 and serves also as a partial protection for the shifting mechanism mounted on the frame 3|. The cover may be mounted by screws which clamp its lowerv edge to the upper wings 3 Ic of the frame.

From Fig. 2 it will be apparent how relatively compact the collet-releasing mechanism may be made and how relatively short a protruding overhang of the spindle is required by my invention where the reciprocating movement given the cam sleeve I8 is only that required for its function of looking and releasing the collet.

The frame 3l and the mechanism mounted on it for effecting the collet releasing and bar feed shifting is also very compact and yet presents the hand lever 39 in a convenient position.

While I have illustrated and described this specic embodiment of my invention, I contemplate that many changes and substitutions may be made Without departing from the scope or spirit of my invention.

I claim:

1. For a, lathe headstock having a hollow spindle with a forward collet and a rearward colletoperating cam sleeve and having associated therewith a bar feed including a ratchet bar, shifting mechanism for the sleeve and for the ratchet bar comprising a frame for attachment to the headstock rearwardly thereof, a transverse horizontal cam shaft journaled in the frame,.=an upstandinghand lever .on the shaft,v a sleeve-operating. cam. on the shaft having.` a .cammingreach andra dwell reach, a shifter controlled bythe cam. forvshifting thesleeve, a ratchet baroperating camwon` the shaft having a camming reach and` a dwell reach, andI a shifter Acontrolled by the lattercamV for progressing the ratchet bar, theshiftingmechansm `being so `constructed and arrangedthatthe camming reach kof each cam is effective, upon its .shifter While the dwell reach of .ther other cam is' effective upon its' shifter, Wherebyxthe ratchet bar and 4thecarnxsleeve are shifted sequentially. l

2.' In a ybar feed land locking device for a hollow-spindledw-lathe vcomprising a collet at the front rend, of Athe spindlaa collet-controlling tube extending through theuspindle, fingers on the rear Y, end ofthe spindle for Ashifting the tube, a cam-sliding sleeve for controlling the fingers `and in turn the flocking :and release of the collet,` a rearwardly extending: guide roda ratchet slid'- ably therealong, `and a feed carriage slidable along thezguide rodrwith pawled engagement with'the ratchet barxand adapted to ,engage a stop on a stock .bar `extending rearwardly' through the spindle,fmechanism for successively shifting the cam sleeve, andratchet lbar comprising a rocker connected.V to thev ratchet bar for shifting it,` a rocher connected tothe cam sleeve for shifting it, a cam shaft having an operatingl lever, cooperating cam meanson--theshaft and on the respectlvef rockers. including successivelyn positioned camming reaches and `dwell reaches constructed and arrangedlupon rotationl of the shaft in one direction, firstxto shift the sleeve releasing the collet-,Without effective shifting of the ratchet barandthen to shift the bar without substantially shiftingthetsleeve, and, .upon return rotation of the shaft,to shift the sleeve for lockingv the collet and; to retrogress` the ratchet bar.

3. 'A n collet control and bar feed shifting,` mechanism constituting: a- .unitary ldevice for attachment to a lathe having a ratchetv bar feed and a collet-controlling sleeve, vand comprisinga frame to be mounted on the end of the headstock beneath the protruding spindle, a collet rocker transversely pivoted on the frame having an upstanding yoke for shifting engagement with a collet-controlling cam sleeve on the spindle, a feed rocker transversely pivoted on the frame having a yoke for shifting engagement with a longitudinally slidable ratchet bar of the bar feed, a horizontal cam shaft transversely journaled on the frame, a hand lever onlthe shaft, and cooperatlng cam elements on each rocker and on the shaft respectively, including sequentially arranged camming and dwell reaches, which, upon swinging the lever in one direction, first rock the collet rocker for shifting the sleeve to colletreleasing position and then, without further substantial shift of the sleeve,"rock the feed rocker to shift the ratchet bar for progressing the bar istock, and, upon return swinging of the lever,

rock the collet rocker to shift the sleeve to colletlocking position and rock the feed rocker to retrogress the ratchet bar.

4. A collet control and bar feed shifting mechanism attachment for a lathe having a ratchet bar feed, comprising a supporting frame adapted to be mounted on the headstock of a lathe, said frame being provided with an actuating shaft rotatably mounted thereon, an actuating handle carried by said shaft, a pair of cam members carried by said shaft and having their active driving portions located to be effective at different angular positions of said handle, one of said cams being a collet controling cam and the other of said cams being a feed controlling cam, a feed controlling lever pivotally mounted on said frame and having one of its ends adapted to actuate the ratchet bar feed and the other of its ends provided with means for engaging the feed controlling cam, a collet controlling lever mounted on said frame and having one of its ends provided with means for actuating the collet controlling sleeve, and the other of its ends provided with means for engaging the collet controlling cam, whereby the actuation of the handle is adapted to release the collet first and then effect a predetermined feed of the ratchet bar feed upon movement in one direction, and upon movement in the other direction the said handle is adapted to return the ratchet bar for a new feed first and thereafter to close the collet.

5. A collet control and bar feed shifting mechanism attachment for a lathe having a ratchet bar feed, comprising a supporting frame adapted to be mounted on the headstock of a lathe, said frame being provided with an actuating shaft rotatably mounted thereon, an actuating handle carried by said shaft, a pair of cam members carried by said shaft and having their active driving portions located to be effective at different angular positions of said handle, one of said cams being a.' collet controlling cam and the other of said cams being a feed controling cam, a feed controlling lever pivotally mounted on said frame and having one of its ends adapted to actuate the ratchet bar feed and the other of its ends provided with means for engaging the feed controlling cam, a collet controlling lever mounted on said frame and having one of its ends provided with means for actuating the collet controlling sleeve, and the other of its ends provided With means for engaging the collet controlling cam, whereby the actuation of the handle is adapted to release the collet rst and then eiect a predetermined feed of the ratchet bar feed upon movement in one direction, and upon movement in the other direction the said handle is adapted to return the ratchet bar for a new feed first and thereafter to close the collet, the said cams comprising a pair of members having the active camming portion formed as the Wall of a slot for engaging complementary members carried by the cooperating levers.

6. A collet control and bar feed shifting mechanism attachment for a lathe having a ratchet bar feed', comprising a supporting frame adapted to be mounted on the headstock of a lathe, said frame being provided with an actuating shaft rotatably mounted thereon, an actuating handle carried by said shaft, a pair of cam members carried by said shaft and having their active driving portions located to be effective at different angular positions of said handle, one of said cams being a collet controlling cam and the other of saidy cams being a feed controlling cam, a feed controlling lever pivotally mounted on said frame and having one of its ends adapted to actuate the ratchet bar feed and the other of its ends provided With means for engaging the feed controlling cam, a collet controlling lever mounted on said frame and having one of its ends provided with means for actuating the collet controlling sleeve, and the other of its ends provided with means for engaging the collet controlling cam, whereby the actuation of the handle is adapted to release the collet first and then effect a predetermined feed of the ratchet bar feed upon movement in one direction, and upon movement in the other direction the said handle is adapted to return the ratchet bar for a new feed rst and thereafter to close the collet, the said cams comprising a pair of members having the active camming portion formedy as the Wall of a slot for engaging complementary members carried by the cooperating levers, and the said slots being formed with dwelling portions for engaging the parts on said levers where movement of the cam is to be ineffective.

HENRY H. LOGAN. 

